CALCIUM-PHOSPHATE CERAMIC COATINGS AS CARRIERS OF VANCOMYCIN

Infection in the setting of total joint arthroplasty remains a challen ging problem. Attention has turned to developing methods of local deli very of antibiotics for prophylaxis. Vancomycin loaded into calcium ph osphate ceramic coatings on titanium alloy substrates is a clinically relevant concept in the setting of total joint arthroplasty. Drug load ing was accomplished by immersion of ceramic-coated discs in vancomyci n-containing simulated physiological solution; in some experiments dru g loading by immersion was followed by lipid coating in egg phosphatid ylcholine solutions. The kinetics of vancomycin release and the effica cy of drug inhibition of Staphylococcus aureus were determined in vitr o in comparison to the release from currently used antibiotic-laden po ly(methyl methacrylate) (PMMA). The loading by immersion provided effe ctive release and inhibition at early time points (up to 24 h); howeve r, the lipid-coated samples demonstrated significant release and effec tive bacterial inhibition up to 72 h. The two-step procedure, i.e. dru g loading followed by lipid coating in order to slow antibiotic elutio n, is more effective than the conventional one-step loading. The study indicated that the osteoconductive calcium phosphate coatings have th e potential to serve as drug carriers to prevent infection in the sett ing of total joint arthroplasty. (C) 1997 Elsevier Science Limited.